Short answer: Work instructions are step-by-step documents that tell a person exactly how to perform one specific task, such as assembling a sub-assembly, replacing a part or inspecting a weld, at the place where the work is done. They list the steps in order, the tools, parts and safety precautions, and the checks to make along the way. They are the most detailed level of a quality management system’s documentation.
Work instructions, SOPs and processes
| Level | What it answers | Example |
|---|---|---|
| Process | What happens, from start to finish, and why? | From order to delivery of an industrial pump. |
| Standard operating procedure (SOP) | Who does what, and when? | Final assembly and test of the pump. |
| Work instruction | How exactly is this one task done? | Fit the coupling guard: six steps, one hex key and a final check. |
ISO 9001 does not require a document called a work instruction. It requires the documented information your organization needs to run its processes, and for hands-on tasks that information usually takes the form of work instructions. For the difference in practice, read how to create SOPs.
What a good work instruction contains
- Identity: a title, an identifier, a revision and an owner.
- Scope: the product, variant and workstation it applies to.
- Safety: warnings, cautions and protective equipment, placed before the step they apply to.
- What you need: tools, parts and consumables, with quantities.
- Steps: numbered, one action each, with a photo, a drawing or a 3D view.
- Checks: what to verify, with the acceptance criteria, such as a torque value.
- Records: fields to sign off the task or report a problem.
An example: replacing a robot arm’s gripper servo
The SO-101 gripper servo replacement is a public work instruction for the open-source SO-101 robot arm. It names the one tool needed, a Phillips-head screwdriver, takes the reader through nine steps in an interactive 3D viewer, and ends with resetting the motor ID and recalibrating. Open it in your browser, with no account, to see what a 3D work instruction looks like. The TwinWorks Community has more, for robot arms, 3D printers and drones.
Paper, PDF, digital and 3D work instructions
Paper and PDF instructions are easy to start with but hard to keep current: every printout and local copy has to be found and replaced. With digital work instructions, operators open the instruction on a screen at the workstation, from one approved version. 3D work instructions add the product model, so the reader sees the exact part and its orientation at each step. Interactive instructions vs PDF manuals compares the formats.
How to write work instructions in six steps
- Pick one task, and the person who does it best.
- Watch them do it, and write down every action, tool and check.
- Split the task into steps of one action each, in order.
- Add a visual to every step: a photo, a drawing or a 3D view.
- Test the instruction with someone who has never done the task.
- Approve it, publish it in one place, and give it an owner and a revision.
Keep work instructions current
Work instructions go out of date when the product changes and the instruction does not. An engineering change order updates the drawing and the bill of materials, but the instruction that shows the same part is often missed. Read why work instructions become outdated, and see how TwinWorks shows the documentation an engineering change reaches.
FAQ
What is the difference between work instructions and an SOP?
An SOP defines the standard way a process runs: who does what, and when. A work instruction gives the step-by-step detail for performing one task within that process.
What should a work instruction include?
A title, identifier and revision; the scope; safety warnings and protective equipment; the tools, parts and consumables; numbered steps with visuals; the checks to make; and fields to record the result.
Does ISO 9001 require work instructions?
ISO 9001 does not require a document called a work instruction. It requires the documented information your organization needs to run its processes effectively, and for hands-on tasks that information often takes the form of work instructions.
What are digital work instructions?
Work instructions opened on a screen, such as a tablet at the workstation, instead of on paper. They can include 3D views, photos and video, and are updated in one place when the product or process changes.
Related terms and pages
Write your first 3D work instruction
Import a 3D model and a reference PDF, let AI draft the steps for you to review, and publish a work instruction your team opens in a browser.